An apparatus for melt mixing and spinning synthetic polymers into filaments from a plurality of spinning nozzle units connected to a melt extruder through a metering pump is described in U.S. Pat. No. 4,017,249. If the characteristics of the fibers should change along their length, the synthetic polymer or additives have to be changed in the extruder. This changes the characteristics of all spun filaments along their length at once. Attempts have been made to change the properties alternately in the direction of the fiber axis. U.S. Pat. No. 4,019,844 discloses an apparatus for producing multiple layers conjugate fibers which have a housing with a rotary cylinder plug and a stationary spinning plate with a plurality of spinning orifices that are positioned and lined up with the passageways of the rotary cylinder plug. This apparatus creates a multiple layer conjugate fibers with parabolic interface. Disadvantage of this apparatus is the use of the rotary cylinder plug with is technically difficult to operate.
Object of the present invention was to provide a cam pump for the production of alternating sequences of polymer flow pulses for melt mixing and spinning synthetic polymers for the manufacture of yarns which are composed of a multiplicity of bundles of filaments, whereby the properties of all filaments in all bundles alternate along their length and the properties of the filaments of each bundle of adjacent bundles alternate between the adjacent bundles.